1. Field of the Invention
The present invention relates generally to semiconductor devices which may be packaged employing tape automated bonding techniques, and more particularly to a bonding pad interconnection structure which allows for placement of at least some bonding pads over active regions of the device.
Tape automated bonding is a method for simultaneously connecting a plurality of bonding pads on a semiconductor device to external circuitry. The method employs a continuous metal tape having individual frames defining metal leads which are arranged in a pattern so that the inner ends of the leads may be bonded to the bonding pads on the device while the outer ends of the leads may be joined to a conventional lead frame or left free to be otherwise connected to external circuitry.
Active circuit elements, including transistors, resistors, and the like, are generally located in the central portion of the semiconductor device, usually referred to as the active region(s). Heretofore, the bonding pads have normally been located around the periphery of the active region so that bonding of the tape leads is less likely to damage the active circuit elements. Such bonding is accomplished by thermocompression techniques, and the resulting heat and pressure would expose underlying circuit elements to potential damage.
In many instances, it would be desirable to be able to locate bonding pads over the active region of the semiconductor device. For example, in order to standardize the arrangement of bonding pads on a variety of different semiconductor devices, it will often be necessary to locate bonding pads over active regions on at least some of the devices. The ability to locate the bonding pads over the device active regions may also simplify design of the metallization layers since it would eliminate the need to connect all bonding pads to the periphery of the device. The elimination of peripheral bonding pads would also allow the construction of semiconductors with smaller die sizes.
For these reasons, it would be highly desirable to provide a bonding pad interconnection structure and method for producing such structure which allows the placement of bonding pads directly over the active regions of the device. In particular, it would be desirable to provide such a structure which will protect the underlying circuit elements in the active region from damage resulting from thermocompression bonding of tape leads in conventional tape automated bonding operations.
2. Description of the Background Art
Tape automated bonding is described in U.S. Pat. Nos. 4,330,790; 4,331,740; 4,355,463; 4,466,183; and 4,470,507.